Vehicle transmissions often have a brake actuated by a piston. The piston is positioned in a housing. An annular return spring is positioned in compression between the piston and its housing to bias the piston to its retracted position. The return spring is sized to fit inside the piston's housing. An annular snap ring holds the return spring in compression between the piston and its housing. The snap ring is contractible to a size where it fits inside the piston's housing, but expands to a size where it partially seats in a groove in the housing, and partially protrudes into the housing to hold the return spring.
During assembly of the transmission, the return spring is positioned against the piston and compressed to expose the housing's groove. The snap ring is contracted, positioned in the housing at the location of the housing's groove, and allowed to expand so that it seats in the housing's groove, with the remainder protruding into the housing to hold the return spring in compression between the piston and its housing.
Transmissions may be a large device with many components therein. The different components have different space requirements. It would be advantageous if the components could be reduced in size thereby providing additional space for other components and/or reducing the size of the transmission.